The structure of the cations from 2– and 4‐pyridones and related pyridines

Abstract

An infrared spectral investigation of 2and 4-pyridone hexachloroantimonates and hexachlorostannates is reported. Protonation of these pyridones occurs on oxygen to form the 2and 4hydroxypyridinium ions, as witnessc:d by the presence of both OH and NH stretching bands.Aromatic ring and skeletal frequencies in these cations correlated very well with those found in other 2and 4-substituted pyridinium hr:xachloroantimonates included in this study.Introduction.

Highly Chromic, Proton-Responsive Phenyl Pyrimidones

“…We investigated 1a – 3c by UV–vis and fluorescence spectroscopy to determine how conjugation between the pendant aryl arms and the pyrimidone core may influence the optical properties of the chromophores. We also obtained spectra in the presence of TFA to examine the effects of monoprotonation at N3 on the optical response of these aromatic molecules. The steric interference between the 6-phenyl and N-ethyl substituents of 1b , 2b , and 3b results in a twisted geometry modulating the interaction of the two aromatic rings, while, in the case of 1a , 2a , and 3a , the π-systems of pyrimidone and phenyl rings should exhibit greater overlap; these effects may be reflected in the optical spectra with changes in λ max, abs or ε.…”